Had problem with venting the LL while for unloading samples. LL pressure would not raise above 3.4Torr. Tried pumping down and venting several times, not successful. Tried command sequence: pump down, transfer samples, transfer samples back, LL Vent, without actually transferring the samples using the arm, this time LL was vented successfully but the gate purge had moved the samples around quite a bit. No samples were lost.